As will be better understood from the following description, the present invention was developed to efficiently and accurately generate three-dimensional digital computer objects from one or more two-dimensional images of the object. Three-dimensional objects are shapes defined in a three-dimensional coordinate space. Three-dimensional objects are rendered onto a display device using a three-dimensional object graphics application that allows a user to change the rendered viewpoint of the three-dimensional object.
Efforts to model the appearance and dynamics of the real world have produced some of the most compelling imagery in computer graphics. In particular, efforts to model architectural scenes have produced impressive walk-throughs and inspiring fly-bys. Exploring an architectural structure without having to spend the time and money to physically travel to the structure is very attractive in many fields, such as corporate real estate sales.
Unfortunately, current geometry-based methods of modeling existing architecture or objects, in which a modeling program is used to manually position the elements of the scene, have several drawbacks. First, the process is extremely labor-intensive, typically involving surveying the site, locating and digitizing architectural plans, or converting existing CAD data. Second, it is difficult to verify whether the resulting model is accurate, and the resulting model noticeably appears computer-generated. Even the processes that employ liberal texture mapping generally fail to resemble real photographs.
Recently, creating digital computer models directly from photographs has received increased interest in computer graphics. Since real images are used as input, such an image-based system has an advantage in producing photorealistic renderings as output. Some of the most promising of these systems rely on the computer vision technique of computational stereopsis to automatically determine the structure of the scene from multiple photographs. As a consequence, however, these systems are only as strong as the underlying algorithms, which have a number of significant weaknesses. In particular, the photographs need to appear very similar for reliable results to be obtained. Because of this, current image-based techniques must use many closely spaced images and, in some cases, employ significant amounts of user input. In this framework, capturing the data for a realistically renderable model requires a number of closely spaced photographs, and deriving the depth from the photographs requires an amount of user input that is inefficient for large-scale model generation. These concessions to the weakness of stereo algorithms bode poorly for creating large-scale, freely navigable virtual environments from photographs in a cost effective manner.
The present invention is directed to overcoming the foregoing and other disadvantages. More specifically, the present invention is directed to providing a method, apparatus and computer-readable medium for generating highly accurate three-dimensional digital computer models or objects from one or more two-dimensional images.